The invention relates to the identification and cloning of human Vpr Interacting Protein (hVIP), to methods of making and using the same, and to compositions and methods of inhibiting their activity in the cell cycle.
Relatively little regarding the function of the viral protein R (Vpr) has been reported since the demonstration that the small open reading frame within HIV-1 designated R encodes a 15 kd protein. Wong-Staal, et al., AIDS Res. Hum. Retroviruses, 1987, 3, 33-39. The vpr open reading frame is conserved within all genomes of HIV-1 and HIV-2 and within most, if not all, simian immunodeficiency virus (SIV) genomes. Vpr is immunogenic in vivo and most if not all HIV+ individuals makes antibodies that can react with eukaryotically produced Vpr protein.
The progression from HIV infection to AIDS is in large part determined by the effects of HIV on the cells that it infects, including CD4xe2x88x92 T lymphocytes and macrophages. On the other hand, cell activation, differentiation and proliferation are in turn thought to regulate HIV infection and replication in T cells and macrophages. Gallo, et al., Science, 1984, 224, 500; Levy, et al., Science , 1984, 225, 840; Zack, et al., Science , 1988, 240, 1026; Griffin, et al., Nature , 1988, 339, 70; Valentin, et al., J. AIDS, 1991, 4, 751; Rich, et al., J. Clin. Invest., 1992, 89, 176; and Schuitemaker, et al., J. Virol., 1992, 66, 1354. Cell division per se may not be required since HIV and other lentiviruses can replicate in nonproliferating, terminally differentiated macrophages and growth-arrested T lymphocytes. Rose, et al., Am. Rev. Respir. Dis., 1986, 143, 850; Salahuddin, et al., Blood, 1986, 68, 281; and Li, et al., J. Virol., 1993, 67, 3969. The ability of lentiviruses, including HIV, to replicate in nonproliferating cells, particularly in macrophages, is believed to be unique among retroviruses and it may be significant that several lentiviruses contain a vpr-like gene. Myers, et al., AIDS Res. Hum. Retrovir., 1992, 8, 373. HIV infection of myeloid cell lines can result in a more differentiated phenotype and increase the expression of factors such as NF-KB which are necessary for HIV replication. Roulston, et al., J. Exp. Med., 1992, 175, 751; and Chantal Petit, et al., J. Clin. Invest., 1987, 79, 1883.
The most evidence for the function of the Vpr protein comes from several studies reporting the activities of HIV strains that have mutations in the vpr gene. It has been reported that mutations in the vpr gene results in a decrease in the replication and cytopathogenicity of HIV-1, HIV-2, and SIV in primary CD4+T lymphocytes and transformed T cell lines (Ogawa, et al., J. Virol., 1989, 63, 4110-4114; Shibata, et al. J. Med. Primatol., 1990a, 19, 217-225; Shibata, et al., J. Virol., 1990b, 64, 742-747 and Westervelt, et al., J. Virol., 1992, 66, 3925), although others have reported mutated vpr gene had no effect on replication (Dedera, et al., Virol., 1989, 63, 3205-3208). Interestingly HIV-2 mutated for vpr has been reported unable to infect primary monocyte/macrophages. Hattori, et al., Proc. Natl. Acad. Sci. USA, 1990, 87, 8080-8084. Transactivation of the HIV long terminal repeat and heterologous promoters by HIV is increased about 3-fold in wild-type versus vpr-negative HIV-1, though the mechanism through which Vpr may transactivate transcription is unknown and may be indirect. Cohen, et al., J. Acquir. Immune Defic. Syndr., 1990b, 3, 11-18. The relationship between the effects of Vpr on promoter activity and viral infectivity is not clear. Vpr protein is incorporated into the viral particle, and this finding has led to the proposition that Vpr functions early in infection, following virus penetration and uncoating, and that Vpr may interact with cellular regulatory mechanisms important in the establishment of infection. Cohen, et al., J. Virol., 1990a, 64, 3097-3099; Yu, et al., J. Virol., 1990, 64, 5688-5693; and, Yuan, et al., AIDS Res. Hum. Retroviruses, 1990, 6, 1265-1271.
The vpr gene of HIV-1 has been shown to induce cellular growth inhibition and differentiation in tumor lines of intermediate differentiation in vitro. Levy, et al., Cell, 1993, 72, 541. Since Vpr protein originates within viral particles, Vpr may play a role in establishing productive infection. In addition, several important possibly interrelated functions have been identified for HIV-1 Vpr. These include import of reverse transcription complex into the nucleus of non-dividing cells, cellular differentiation, cell cycle arrest at the G2/M phase, and enhancement of HIV-1 replication.
HIV-1 Vpr is required to import the viral preintegration complex into the nucleus of non-dividing cells (Heinzinger, et al., Proc. Natl. Acad. Sci. USA, 1994, 91, 7311-7315; and Fletcher, et al., EMBO., 1996, 15, 6155-6165) and it enhances viral replication in monocyte cell lines (Balotta, et al., J. Virol., 1993, 67, 4409-4414; Balliet, et al., Virology, 1994, 200, 623-631; and Connor, et al., Virology, 1995, 206, 935-944). Vpr localizes to the nucleus and induces cellular differentiation subsequently arresting cells at the G2/M phase of the cell cycle. Lu, et al., J. Virol., 1993, 67, 6542-6550; Mahalingam, et al., Virology, 1995, 212, 313-339; DiMarzio, et. al., J. Virol., 1995, 69, 7909-7916; Levy, et al., Cell, 1993, 72, 541-550; Rogel, et al., J. Virol., 1995, 69, 882-888; Jowett, et al., J. Virol., 1995, 69, 6304-6313; Mahalingam, et al., DNA Cell Biol., 1997, 16, 137-153. Mutational analysis suggests that the functions of this 96 amino acid Vpr protein are mediated through interactions with appropriate cellular cofactor(s). Zhao, et al., J. Biol. Chem., 199, 269, 15577-15582; Refaeli, et al., Proc. Natl. Acad. Sci. USA, 1995, 92, 3621-3625; He, et al., J. Virol., 1995, 69, 6705-6711; Re, et al., J. Virol., 1995, 69, 6859-6864.
There is a need to identify novel compounds which inhibit HIV replication. Specifically, safe and effective compounds are sought which reduce replication by interfering with particular molecular signals mediated by Vpr. Likewise, safe and effective compounds are sought which interfere with the cofactor with which Vpr interacts, which is an essential component of the cell cycle cascade. Moreover, there is a need to identify the co-factor and target it in methods of modulating the cell cycle. There is a need for compounds and methods for inhibiting the progression of the cell cycle from G2 to M phase in cells whose proliferation is undesirable such as hyperproliferating cells.
In the present invention, a yeast two-hybrid assay was utilized in an effort to identify specific cellular cofactors which interact with Vpr. Three clones that fulfilled criteria essential for a Vpr ligand, containing overlapping complementary DNA derived from the same gene, were isolated. The protein encoded by this cDNA was designated hVIP. Various Vpr mutants were tested for the ability to arrest the cell cycle and colocalize with hVIP in different human cell lines. A direct correlation was found between the inhibition of cellular proliferation and the colocalization of Vpr mutants with hVIP. Suppression of hVIP expression in cycling cells arrest cells in G2/M phase. hVIP was found to be necessary for the transition from G2 to M phase and therefore is an essential component of the cell cycle cascade.
The present invention relates to substantially pure hVIP, and fragments thereof.
The present invention relates to isolated nucleic acid molecules that encode hVIP, or a fragment thereof.
The present invention relates to nucleic acid probes and primers directed to nucleic acid molecules that encode hVIP, or a fragment thereof.
The present invention relates to oligonucleotide molecules that consist of a nucleotide sequence complementary to a portion of the nucleotide sequence that encodes hVIP.
The present invention relates to vectors comprising nucleic acid molecules encoding hVIP.
The present invention relates to recombinant expression vectors that comprise nucleic acid sequences that encode hVIP,
The present invention relates to host cells that comprise recombinant expression vectors which include nucleic acid sequences that encode hVIP.
The present invention relates to genetic therapy vectors comprising nucleic acid molecules encoding hVIP.
The present invention relates to isolated antibody which binds to an epitope on hVIP.
The present invention relates to pharmaceutical compositions comprising a pharmaceutically acceptable carrier and nucleic acid molecules complementary to a portion of hVIP.
The present invention is related to methods of making hVIP.
The present invention is related to methods of inhibiting expression of human Vpr Interacting Protein with oligonucleotides complementary to a portion of the nucleotide sequence that encodes hVIP.
The present invention relates to fragments of Vpr which interact with hVIP to prevent or inhibit G2/M transition by cells.
The present invention relates to pharmaceutical compositions which comprise fragments of Vpr which interact with hVIP to prevent or inhibit G2/M transition by cells.
The present invention relates to isolated nucleic acid molecules that encode fragments of Vpr which interact with hVIP to prevent or inhibit G2/M transition by cells.
The present invention relates to vectors comprising nucleic acid molecules encoding fragments of Vpr which interact with hVIP to prevent or inhibit G2/M transition by cells.
The present invention relates to recombinant expression vectors that comprise nucleic acid sequences that encode fragments of Vpr which interact with hVIP to prevent or inhibit G2/M transition by cells.
The present invention relates to host cells that comprise recombinant expression vectors which include nucleic acid sequences that encode fragments of Vpr which interact with hVIP to prevent or inhibit G2/M transition by cells.
The present invention relates to genetic therapy vectors comprising nucleic acid molecules encoding fragments of Vpr which interact with hVIP to prevent or inhibit G2/M transition by cells.
The present invention is related to methods of making fragments of Vpr which interact with hVIP to prevent or inhibit G2/M transition by cells.
The present invention is related to methods of inhibiting cells from transitioning from M to G2 comprising contacting cells with a fragments of Vpr which interact with hVIP to prevent or inhibit G2/M transition by cells or a nucleotide sequence that encodes fragments of Vpr which interact with hVIP to prevent or inhibit G2/M transition by cells which is expressed by the cells.
The present invention relates to methods of identifying anti-HIV compounds that comprise the steps of contacting hVIP or a fragment of HIV known to interact with Vpr with Vpr or a fragment of Vpr which interacts with hVIP to prevent or inhibit G2M transition by cells in the presence of a test compound and comparing the affinity of hVIP or fragment thereof with Vpr or fragment thereof to the affinity of hVIP or fragment thereof with Vpr or fragment thereof in the absence of a test compound.